Power Transmission—Slippage-Abrasion. An Investigation of the Abrasion of Tread Compounds

Abstract The abrasion behavior of vulcanizates of the tire-tread type have been studied by the method of constant energy, with a test apparatus operating on the principle of the Dunlop-Lambourn machine. As a result of this work, the following facts were established. Up to a critical slippage, the value of which is characteristic of every individual vulcanizate, the abrasion, i.e., the amount of rubber worn off per unit of time, increases with the square of the slippage. The slippage increases linearly with the power transmitted. To this quadratic relation between the power transmitted and the slippage corresponds a linear dependence of the abrasion power, i.e., it is possible to assign a specific abrasion energy to every individual vulcanizate. The specific abrasion energy is inversely proportional to the temperature and also inversely proportional to the mean particle size of the abrasive material. A comparison of the measured specific abrasion energy with the corresponding value to be expected by theoretical calculation shows that the experimental value is too high by a factor of 106. From this, one is led to the conclusion that the abrasion power is practically completely consumed as heat in the abrasion boundary layer, an idea which is supported by measurements of the temperature of abrasion and a comparison of this with the calculated values. Above the critical slippage value, the simple linear dependence of the abrasive wear on the abrasion power no longer holds true, and a specific abrasion energy cannot be defined. In addition, the abrasion patterns described by Schallamach then appear, and any correlation between laboratory tests and road wear tests is lost.